This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. xc2xa7119 from my application DOCKING SYSTEM OF PORTABLE COMPUTER filed with the Korean Industrial Property Office on Nov. 10, 1999 and there duly assigned Serial No. 49716/1999.
1. Field of the Invention
The present invention relates to a docking system for a portable computer and, more particularly, to a docking system for a portable computer having an improved bus sharing structure between the portable computer and the docking station so that a program can be executed in real time and data and peripheral devices can be shared.
2. Description of the Related Art
In general, a portable computer has a reduced number of functions and is made to be easy to carry compared to a desk top computer. Within the class of portable computers, there are notebook computers, personal digital assistants (PDAs), and handheld personal computers (HPCs).
A typical PDA includes a microprocessor and a memory, such as a random access memory (RAM) and a read-only memory (ROM), for storing and processing information, and the information is input through a touch screen. The PDA uses an information storage device, such as a flash memory, instead of auxiliary storage, such as a hard disk drive (HDD). The information storage device is small and does not require an additional driving apparatus.
A typical HPC is provided with a personal information management system (PIMS), as well as a word processor or a communications program. The HPC is usually used to assist a desk top PC or a notebook computer.
The PDA and HPC having the above structures are used by being connected to a desk top PC or a notebook computer via a serial port or an infrared ray port.
As shown in FIG. 1, a docking system for a conventional portable computer includes a portable computer 10, such as a typical PDA or HPC, and a desk top computer 20 at which the portable computer 10 is docked. Referring to the drawing, the portable computer 10 is small and includes a microprocessor 11, such as a CPU, and a memory, such as RAM 12 and ROM 13, for processing and storing information, a touch screen 14 for inputting information, and an LCD device 16 for displaying information. The portable computer 10 also includes a port I 15 for the connection to a desk top computer 20, which will be described later, and which may be either a serial port or an infrared ray port. A flash memory 17 and buffer 18 are also provided.
The desk top computer 20, which has high performance and multiple functions, includes auxiliary storage devices such as a hard disk drive (HDD) 21 or a CD-ROM 22, various extension slots, and ports, in addition to a microprocessor 23 and a memory 24. The desk top computer 20 also includes a port II 25 connected to port I 15. Other components are ROM 24a, AGP 24b, AL BUS FOR VGA 24c, DMA 26a, I/O port 26b, timer 26c, PIC 26d, keyboard 26e, SCSI 27, and buffers 28a, 28b and 29.
In this docking system, each of the portable computer 10 and the desk top computer 20 has a separate microprocessor, thus forming independent systems. By electrically connecting the port I 15 and the port II 25 in series, data is not transmitted therebetween in a real time manner.
In the docking system for the conventional portable computer having the above structure, because the portable computer 10 and the desk top computer 20 are operated separately, it is a drawback that only data transmission is possible between the computers 10 and 20. Also, since data cannot be transmitted in real time, a program cannot be executed in real time. Thus, it is inconvenient that communication between the computers 10 and 20 is only accomplished by means of downloading.
Also, only a limited amount of work is possible when a program of the portable computer 10 is executed since such resources as the HDD 21 and I/O (input/output) devices, memory or ports of the desk top computer 20 cannot be used. The portable computer 10 uses software stored in the ROM 24a, and the number of software programs available is limited when the portable computer 10 is purchased. Thus, a particular application performed on the desk top computer 20 which has improved performance may not be executed on the portable computer 10. Also, since the microprocessors 11 and 23 of the portable computer 10 and the desk top computer 20, respectively, are different from each other, compatibility is lowered. Furthermore, the function of the portable computer 10 is limited as to upgrading, and even when the performance of extension units, such as a video card, a sound card, a LAN card or an I/O device of the desk top computer 20, is improved, the improved extension units cannot be used.
To solve the above problems, it is an objective of the present invention to provide a docking system for a portable computer in which the bus sharing structure between the portable computer and a docking station and the structure of the docking station are improved so that the real time execution of a program and the sharing of data and peripheral devices are possible.
Accordingly, to achieve the above objective, there is provided a docking system for a portable computer which comprises: a docking station, including an auxiliary storage device wherein a first operating system is stored, I/O devices, a plurality of extension slots and a plurality of ports, and excluding a microprocessor and a memory; a portable computer including a ROM wherein a second operating system is stored, a microprocessor, a memory wherein commands and data are stored in an electronic method, and a docking controller for selecting one of first and second operating systems according to whether the portable computer is docked at the docking station; and first and second signal transmitting units provided at the portable computer and the docking station, respectively, for performing the transmission and receiving of data between the portable computer and the docking station.